Transmitter arrangement for guiding airplanes



M. LOCK 2 She'ets-Sheehv 1 Filed March 9, 1935 INVENTOR M ICHAE LOCK BY 7 /I/YW ATTORNEY TRANSMITTER ARRANGEMENT TOR GUIDING AIRPLANES Get. 26, 1937. M. LOCK 2,097,072

TRANSMITTER ARRANGEMENT FOR GUIDING AIRPLANES Filed March 9, 1935 2 Sheets-Sheet 2 7() ggdga lNvEN'roR MICHAEL LOCK TTORNEY Patented Oct. 206, 1937 UNITED STATES PATENT OFFICE TRANSMITTER ARRANGEMENT FOR GUID- ING AIRPLANES Germany Application March 9, 1935, Serial No. 10,197

In Germany March 10, 1934 3 Claims.

'I'he present invention is concerned with means adapted to guide aircraft along definite courses, say, for guiding them towards the approach to airports or for shunting them in the case of obstacles.

'I'he directrix or guide-line according to the present invention is formed by the longitudinal' axes of a row of vertical radiators designed toY produce narrow beams and whose identification or modulation indicates the approximate horizon'- tal distance from a spe'cial point, such, for example, as an intended landing point at an airport.

For defining and fixing a fiying course and guide-line, methods are known in the prior art in which a single radiator or beacon is employed for the purpose of identification. Methods of this kind involve the draw-back that the beam or radiation cone presenting a. small angle of inclination in reference to the horizontal becomes so wide (in proportion to greater distance from the transmitter or beacon) that it is very -inconvenient to use it as a guide line. For the purpose of orientation, it is necessary to fiy considerable distances towards the right or the lefthand side in order that lateral departures may be safely ascertained.

Moreover, methods are known in the -art in which two divergent beams are used for forming the guide line` in such a Way that, with dissimilar identications of these beams, a permanent signal is produced in the receiver along the line of unvaried signal, that is, along the equisignal zone.

H`owever, all of these methods do not afford any clues whatever regarding the distance of the airplane from an airport, or obstacle to be particularly kept under observation. They do not allow of any clear clues respecting the direction of flight or course, that is to say, whether the plane is travelling towards, or else away from, the destination. Under such conditions and with blind flying serious piloting errors are apt to be made.

In German Patent #507,501, a method has been disclosed which is adapted to position-nding of craft. This patent discloses a system in which the territory to be covered by an airplane is divided in accordance with a rectangular coordinate system into elementary areas. To each one of these latter is c'o-ordinated a constituent transmitten'and each of these beacons or transmitters has its own identification. It will be understood that such a method involves a great deal of material and installation, and a local indicator comprising a. great number of resonant (Cl. Z50-11) systems, and these, in turn, divert a great deal oi attention on the part of the pilot which may be required for other work. Another point is that, inasmuch as there is no standard size or shape for airports and landing fields, etc., it fol- '6 lows that a specially designed local indicator system will be needed for each individual airport.

By the present invention, in addition to a simplified guiding of airplanes, determination of position in the sense of distance determination is to be made feasible.

The transmitter or beacon arrangement alccording to this invention designed for the guidance of aircraft along a preferred course consists in the feature that the line of iiight is covered or studded with a row of vertical radiators. Now the radiation characteristic of each individual radiator is so formed and designed that a horizontal section results in a shallow ellipse whose longitudinal axis coincides with or falls within the guide line. For determining distance each individual radiator is provided with its own identification, say, by dissimilar wave-lengths, or, in case the same wave-length is used throughout, by dissimilar modulation. Identi'cation should 25 be preferably so chosen that it will be possible to tell immediately at what distance the craft happens to be from the goal or destination, and whether the course is towards or away from the latter, and this is extremely important in case of blind fiying in foggy weather.

The present invention is particularly suited for guiding or piloting airplanes towards landing fields and for steering them so as to circumvent obstacles liable to endanger the ight of a plane. For this purpose it is advisable to enlarge the guide-,line at greater distances from the goal and at right angles to the main approach so to obtain a suitable guide zone. According to one method of doing this, as shown, for instance, in 40 Fig. 1a, the beam at right angles tothe guide line is allowed to diminish so that a sort of collector funnel results. In this manner it will be an easy matter for the pilot to safely reach the guide-line itself. In case the airplane should occasionally happen to drift into the guide-line from the side, the pilot will be'readily enabled from the identification signal'of the radiators to tell at what distance from his goal he has struck the guide-line. Thus, an identification signal may be chosen having a sequence characteristic corresponding to the distance (5 km=5 dots).

However, the practical use of' the invention is not confined to aerial navigation (or avigation) but will be found useful also for the piloting of ships through channels between cliiis, and amongst submergedrocks, mine elds, etc. w

Figs.. l to 3 show by way of example a number lof practicalernbodiments of transmitter or beacon arrangements of. the kind here disclosed.

Fig. 1a, for instance, is a plan view of'an airr port l with part of a guide-line a, b; `formed by yseparate elongated iields produced by radiators 2, 3, l, and 5. In a modified scheme a pilotingy strip orzone e, c, e, d, is produced by elongated fields whicli-r areenlargedas shown by ldotted lines to result in a guide funnel.

. F1a-1b shows in elevation cooking at right Fig. 2a' shows a plan of Vairiairport yi `and the individual radiators. 2 andy! adjacent the goal (l). Atthe end .of the radiation zone. 2 turned -towards the goal or destination there may be interposed advantageously an identiiication beacon S- consisting oia strongly beamed circular` in. dlvidual radiation 'disposed at right angles .to .f the guide-line with a shallow beam whereby the pilot .is ailorded a signal instructing =him to get set for the direct landing.y f

--Figure 2b shows an eievacmnview. At points -f2 and 3. respectivelvbeams of radiation are pro-` jected upwardly and expanding as they rise in a altitude.` Theexpansion is greater in the di-1 rection of 'intended .night= of an airplane ap.

preaching a landing eld.r However, the sources -2 andi are spaced apart sufiiciently so that' there is no overlapping of .the beams.

the region overlying .the airport I. This beam.

therefore, possesses. a verticallydisposed margin `line adjacent said region.

tional. beam -6 may be provided between the beamy It desired, an addiorder that a plane dying through successive beams may be'able to distinguish first one and then another until it reaches and traverses the beam B which gives an indication o! the boundary of said airport or landing iieid.

Fig. 3a shows a plan oi' the landing eld l and the individual radiator 2 closest to the goal.

The-beam from. Athe source 2 is .preferably inclined away. fromadjacent said region.r 1 I' Upon both sides ofthe said individual radiator 2=radiators l and 8 radiating at an oblique angle tion (looking fromv the landing'iield l in the di-4 rection of the guide-line a, b) shows-the vertical radiator .2 andthe twolateral radiators 'I and l. The three cones of radiations rbound ra deilniteA =altitude, layer j, the means height -h 0I which is la functionl ofthe-angie a ofthe radiators I and 8. in reference to the ground,r and ofthe lateral distance son the ground. In this particular I altitude `layer they identification signals of the three radiators, for instance,y may result in a permanent signal-so that the pilot receives altitude data in addition to distance data.

At'the end oi the .radiationl cone 2 l(direction l towards the goal)` which is characterized by the identincation beacontor elseby theendoi the permanent-'signal producedy by 2", 1, l, the `pilot.y

must then get set for a direct landing, say, along signal strength or 'by' means' of lsome other I claim: -L An aerial navigation system comprising a,

plurality of sources ofconcntrated radio beams.

each of said` sources being adapted. to radiate its beam upward from' the' ground with a` narrow overlying an adjacent landing eld that said beampossessesasubstantiallyvertical margin 2.. A system m` accordance .with claim 1y and `having-means.including an additional `radio beam source yfor projecting energy substantiallyvertically in a pencil of circular cross section out of contact with, but closely adjacent the vertical marginofthatbeamwhichpossessesaninclined axis.

3 Asysteminaccordancewithclaim1and havingsaidradiobeamsourcessocharacterized that each source, starting with vthe one second from the landing eld, projects its beam more expansivelythandoesthepreoedingsourceina plane transverse to the direction of flight.

MICHAEL 100K.

r,are provided.y Figp3b being. a transverseelevai 20y la guidefline or rone-identiable by. aconstant .elliptical cross section having the major axis f thereof coincident` with a direction `ofilight to -be indicated, said' sourcesbe'ing so spacedapart andso aimed that their beams are substantiallyy separated one from another, andthe 'axis ofone rof said-'beams isso inclined away from the region 

